基于土的动应力一应变关系——Davidenkov骨架曲线,采用破坏剪应变幅上限值作为分界点,对Davidenkov骨架曲线进行了修正,即当剪应力值大于破坏剪应力值时,土体产生破坏,土体的动剪切模量采用破坏后的动剪切模量;参考Mashing法则,构造了修正后的Davidenkov骨架曲线土体加卸载对应的应力一应变滞回圈曲线。基于ABAQUS软件的操作平台,开发了土体动弹塑性本构模型的子程序。选择南京某个典型软弱场地为研究对象,首先输入余弦加速度时程曲线,然后选取一条强震加速度记录作为基岩输入地震动,对不同峰值加速度水平下该场地的地震反应进行了二维有限元非线性分析,计算结果验证了所建模型的准确性和可用性。
Based on the one dimension dynamic stress-strain relation Davidenkov skeleton curve, which is corrected by using sectional functions; and the upper limit of failure shear strain amplitude is used as the sectional point. The dynamic shear stress-strain circle curves are constituted by referencing Mashing rules and implemented by sub-program based on ABAQUS finite-element software. A representative soft site in Nanjing City is selected; and its dynamic nonlinear response are calculated when a cosine time-history curve and seismic acceleration waves with different peak values are inputted from bedrock interface. The results prove that the developed dynamic elastoplastic constitutive relations of soil are feasible and accurate; and it can be used to investigate the nonlinear earthquake response analysis of general site.